Textile yarn carriers with anodized surfaces



July 14, 1970 TL 0. WILLIAMS 3,520,490

TEXTILE YARN CARRIERS WITH ANODIZED SURFACES Filed May '7, 1968 2 Sheets-Sheet 1 INVENTOR. THOMAS: C. -/\L.L\AM$ ATTORNEYS July 14, 1970 T. c. WILLIAMS 3,520,490

TEXTILE YARN CARRIERS WITH ANODIZED SURFACES Filed May 7, 1968 2 Sheets-Sheet 2 INVENTOR. THOMAS C. LUAME:

BYMX Z fill 4 ATTORNEYS United States Patent Office US. Cl. 242118.32 7 Claims ABSTRACT OF THE DISCLOSURE The yarn engaging portions of textile yarn carriers are protected against nicking and scratching damage, such as might otherwise occur during handling, storage or removal of residual amounts of yarn therefrom through the use of a sharp instrument, by a very hard layer of anodically produced oxide. The layer of oxide has a scratch hardness of approximately 9 on the Mohs scale, and a density and thickness within predetermined ranges of values.

This application is a continuation-in-part of a copending application entitled Pirn filed Jan. 31, 1967 under Ser. No. 612,904 now abandoned.

- In certain segments of the textile industry, particularly where synthetic fibers are used, textile yarn is transported from a fiber producer to a fiber user in packages formed by winding the yarn around carriers, including types of yarn carriers known as bobbins, pirns, and warp beams. Conventionally, yarn carriers used in such packaging are repeatedly shipped back and forth between a fiber producer and fiber user, and for this reason are made of relatively lightweight materials to reduce the tare weight involved in such shipments.

In handling and storing any such yarn carrier made of the light metals such as aluminum, and particularly in the storage and handling of warp beams, scrapes and collisions between carriers or between a carrier and a harder or sharper obstacle such as a steel rack result in scratching and nicking the exposed surfaces of the carrier. As to flanged spools in general and warp beams in particular, yarn is wound on the carriers under such tension that the wound body of yarn exerts a force longitudinally of the carrier suflicient to bow the end flanges thereof outwardly and thus the layer of yarns immediately adjacent the end flanges or heads is forced into any surface irregularity on the yarn engaging face of the heads. Surface irregularities, resulting from scrapes and collisions as mentioned above, have presented such a problem of snagging yarns in the past as to cause fiber producers to employ repair personnel solely for the purpose of polishing or refinishing the yarn engaging surfaces of warp beam flanges after the beams are returned to the fiber producer but before yarn is wound thereon.

Residual amounts of yarn are conventionally removed from yarn carriers generally, and bobbins and pirns in particular, by cutting the yarn from the carrier with a knife. It has been recognized heretofore that such removal of residual amounts of yarn results in nicking and scratching damage to pirns, and the pirns now in use by the textile industry have a replaceable thin plastic sleeve encircling a supporting metallic body structure. Nicks or scratches in the yarn engaging surface of the plastic sleeve ultimately result in damage to yarns wound on the pirn, and require that the sleeve be discarded and replaced, with accompanying problems of cost, supply, and handling.

With the aforementioned discussion in mind, it is an Patented July 14, 1970 object of the present invention to provide a yarn carrier having yarn engaging surfaces which are protected against nicking and scratching damage such as may occur during handling, storage or the removal of residual amounts of yarn. In accordance with this invention, such protection against damage is obtained by providing, on the yarn e11- gaging surface or surfaces of the carrier, a very hard surface coating or layer which has a scratch hardness of approximately 9 on the Mohs scale and thus is not easily scratched, nicked or scraped in handling of the carrier.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of a pirn incorporating this invention;

FIG. 2 is an enlarged sectional view of a portion of the wall of the pirn of FIG. 1, taken substantially as indicated by the line 2-2 in FIG. 1;

FIG. 3 is a sectional view of the portion of the pirn wall of FIG. 2, taken substantially as indicated by the line 3-3 in FIG. 2;

FIG. 4 is a view similar to FIG. 1, of a warp beam incorporating this invention; and

FIG. 5 is an enlarged sectional view similar to the view of FIG. 2, taken through the warp beam of FIG. 4 substantially as indicated by the line 5-5 in FIG. 4.

While yarn carriers embodying the present invention may take any of a variety of structural configuration, of which the pirn generally indicated at 10 (FIG. 1) and the warp beam generally indicated at 20 (FIG. 4) are nonlimiting illustrations, this invention contemplates that portions of the carriers defining yarn engaging surfaces be made of anodically oxidizable metal. As herein used, the term anodically oxidizable metal refers to a metal selected from that group consisting of aluminum, magnesium, and alloys thereof which are conventionally treated by an electrochemical oxidation process generally known as anodizing. Preferably, the anodically oxidizable metal from which the yarn engaging surfaces of the yarn carriers of this invention are made is a predominately aluminum alloy.

Referring now more particularly to the pirn 10, the pirn includes a tubular yarn supporting member 11, the yarn engaging exterior surface of which has a layer 12 of anodic oxide of the metal of the member 11 formed integrally therewith. This exterior oxide surface is the surface about which yarn packaged on the pirn 10 is wrapped, from which residual amounts of yarn are removed (typically by manual cutting of the yarn by a knife), and which is exposed to possible injury during handling and storage of the empty pirn.

In order to facilitate retention of yarn wound about the pirn 10 and to prevent slippage thereof, the sliding frictional characteristics of the exterior surface of the tubular support member 11 are enhanced in that the surface is somewhat roughened, such as by the provision of a plurality of annular grooves 13 spaced longitudinally along the tubular support member. The grooves 13 function to prevent undue slippage of initial layers of yarn longitudinally of the pirn 10, during a winding operation, and are preferably formed in the tubular support member 11 prior to the subjection of that member to the anodizing process.

In order to protect the tubular yarn supporting member 11 and the surface of the oxide layer 12 from nicking and scratching damage such as would occur during removal of risidual amounts of yarn therefrom, the oxide layer 12 has a scratch hardness of approximately 9 on the Mohs scale, and thus is quite diflicult to nick or score with conventioinal tools such as yarn cutting knives or by collision and impact with other pirns or objects. This scratch hardness of approximately 9 is obtained through forming the oxide layer to have a density and thickness within predetermined ranges. The thickness of the oxide layer or coating is conventionally measured in thousandths of an inch, while the weight disposition of oxide on the yarn supporting member 11 is conventionally measured in milligrams per square foot of surface area. Due to a chemical reaction between the electrolyte used in the process of forming the oxide layer and the oxide layer which is formed, it is characteristic for such a layer to have a greater porosity at an external surface than at an interface between the oxide layer and the base metal. While the weight disposition of oxide thus varies incrementally through the thickness of a layer, it is possible to determine an average figure, in milligrams per square foot, for the layer as an entity. Accordingly, an indication of density may be expressed in terms of milligrams per square foot per thousandth of an inch thickness, based upon the average value of Weight deposition and the finite thickness.

Expressed as ranges of density and thickness, oxide layers having a scratch hardness of approximately 9 have been found within the range of from about 42 to 45 milligrams per square foot per thousandth of an inch thickness and within the range of from .002 to .004 inch thickness. Preferably, the oxide layer provided on the yarn supporting member of a yarn carrier in accordance with this invention has a thickness of approximately .0035 inch and a density of approximately 44 milligrams per square foot per thousandth of an inch thickness.

It is contemplated that an anodic oxide layer formed on a yarn supporting means such as the tubular member 11 can have, as a result of the chemical reaction mentioned briefly above, a surface porosity so high and a surface Weight deposition so low as to present the possibility of crushing of the surface of the layer. Should such a condition be found, the portion of the layer having the high porosity and low weight deposition may be removed by lapping, honing or other similar surface treatment. As it is presently believed that such difliculty will be encountered only as the thickness of the anodic oxide layer is increased, such removal of a surface portion is not forseen as detracting from the protection afforded to the yarn engaging surfaces. particularly as it is anticipated that the remaining portion of the layer will be found to have the scratch hardness characteristics of the oxide layers described herein.

For purposes where scratch hardness is not to be significant, anodic oxide layers usually are approximately .001 inch thick and have a density of approximately 35 milligrams per square foot per thousandth of an inch thickness. By way of illustrating the contrast in electrochemical processes, and not by way of limitation, a conventional anodic oxide layer may be formed by using a current density of 12 amperes per square foot while a workpiece is immersed in an electrolyte of 15% to 18% sulphuric acid at 70 F. An anodic oxide layer as contemplated by this invention may be formed by using a current density of 36 amperes per square foot while a workpiece is immersed in an electrolyte of 12% sulphuric acid and 1% oxalic acid at 40 F.

Another of the structural configuruations which a yarn carrier embodying the present invention may take is that of a warp beam 20 (FIGS. 4 and 5). As there illustrated, the structure of the warp beam is somewhat similar to that disclosed in US. Pat. No. 2,683,573, wherein a pair of yarn supporting end flanges or beam heads 21 and 22 are secured to a tubular yarn supporting beam body 20 by threaded engagement (FIG. 5). While the manner of securing the heads 21 and 22 to the tubular body 23 of a warp beam may be selected from any of a large number of structures known in the prior art, the structure shown in FIG. 5 has been selected only as an example of one manner in which a flanged spool structure such as is employed in a warp beam may be assembled. Further, While a Warp beam conventionally is of relatively large size, substantially the same struuctural configuration will frequently be found in smaller yarn carriers employed as bobbins. Accordingly, the term flanged spool has been adopted herein for use with reference both to the relatively large warp beams and to smaller bobbin structures and the like. While a flanged spool may be an assembly of three or more yarn supporting members, as herein illustrated, such a spool may also be cast or otherwise formed as a unitary structure.

As mentioned briefly above, the tension under which synthetic yarns are frequently Wound on flanged spools such as the warp beam 20 is so high that considerable force is exerted by the wound body of yarn in a direction parallel to the central axis of the main tubular body 23 of the beam. Accordingly, the layer of yarn immediately adjacent the yarn engaging inner radial faces 21a and 22a of the beam heads 21 and 22 is forced into any nicks, scratches, or other depressions in those yarn engaging surfaces. As a consequence of being forced into such surface irregularities, the yarn snags or hangs up when an attempt is made to remove the yarn from the beam 20. It is the necessity of avoiding such snagging or hanging up which has heretofore led synthetic fiber producers to employ persons in refinishing or touching up the yarn engaging surfaces of warp beams.

In accordance with the present invention, the beam heads 21 and 22 and preferably also the main tubular body 23 of the warp beam 20 are made of an anodically oxidizable metal. It is preferred that the anodically oxidized metal be an alloy which is predominately aluminum, for the best combination of strength, lightness and economy. The yarn engaging surfaces of the yarn engaging members including the beam heads 21 and 22 and the main tubular body 23 are then provided with a hard surface coat or layer 25 of anodic oxide of the metal of those members, within the ranges of density, thickness and Mohs scratch hardness described above with reference to the pirn 10. For convenience and to achieve a uniform appearance, it is preferred that the anodic oxide layer also extend around the exterior surfaces of the beam heads 21 and 22, although not necessary on those surfaces for protection of yarn wound on the flanged spool carrier.

In the drawings and specification, there have been set forth preferred embodiments of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. A textile yarn carrier protected against nicking and scratching damage of yarn engaging surfaces and against consequential snagging of yarn comprising yarn supporting means of anodically oxidizable metal and a layer of anodic oxide of said metal defining a yarn engaging surface on said yarn supporting means, said anodic oxide layer having a thickness within the range of from 2 to 4 thousandths of an inch, a density within the range of from about 42 to 45 milligrams per square foot per thousandth of an inch thickness, and a scratch hardness of approximately 9 on the Mohs scale.

2. A yarn carrier according to claim 1 wherein said carrier is a pirn and said yarn supporting means is a predominantly aluminum tube.

3. A yarn carrier according to claim 2 wherein said yarn supporting means is provided with a roughened exterior surface to prevent slippage of yarn thereon.

4. A yarn carrier according to claim 1 wherein said yarn carrier is a flanged spool and said yarn supporting means comprises a pair of end flanges having at least the opposed inward faces thereof provided with said anodic oxide layer.

5. A yarn carrier according to claim 4 wherein said yarn supporting means is predominantly aluminum and further comprises a tubular barrel connecting said end flanges and said anodic oxide layer extends Over the entire exterior surface thereof.

6. A yarn carrier according to claim 1 wherein said layer of oxide is formed with a minimum density of at least about 44 milligrams per square foot per thousandth of an inch thickness and with a minimum thickness of at least about 3 /2 thousandths of an inch.

7. A textile yarn carrier protected against nicking and scratching damage of yarn engaging surfaces and against consequential snagging of yarn comprising yarn supporting means of anodically oxidizable metal and a layer of anodic oxide of siad metal defining a yarn engaging surface on said yarn supporting means, said anodic oxide layer having a minimum thickness of at least about three and one-half thousandths of an inch, a minimum density of at least about 42 milligrams per square foot per thousandth of an inch thickness, and a scratch hardness of approximately 9 on the Mohs scale.

References Cited UNITED STATES PATENTS 1/ 1925 Snyder 242-1 18.3 2/1940 Scholl 242118.7 12/1941 Crooks 242l.18.4 12/1959 Taylor 204-58 9/1963 Portal 242-118.62 3/1966 Manhart 204-58 10/1968 William et al.

FOREIGN PATENTS 15 GEORGE F. MAUTZ, lrimary Examiner U.S. Cl. X.R. 

